Global energy concerns have prompted increasing efforts to develop processes to produce alternative forms of liquid fuels, such as those derived from coal. In such processes, multiple fluid phases are present in essentially all stages of feed preparation, conversion reactions, and product separation. The effective design and operation of such conversion processes require accurate knowledge of the phase behavior of the fluid mixtures encountered. Studies of the solubilities of light gases in heavy hydrocarbons are also of interest in the processing of petroleum products, enhanced oil recovery, and supercritical fluid processes. Solubility data are presented for methane in each of four aromatic hydrocarbons, including benzene, naphthalene, phenanthrene, and pyrene. The measurements cover temperatures from 323 to 433 K at pressures to 11.3 MPa. The data for methane in benzene are in reasonable agreement with the earlier measurements of Sage, while data for phenanthrene are in excellent agreement with those of Malone. The solubilities are described with a root-mean-squared error of 0.001 in mole fraction by the Soave-Redlich-Kwong and Peng-Robinson equations of state when one interaction parameter is used over the complete temperature range for each binary system. Henry's constant and partial molar volumes at infinite dilution were also calculated onmore » the basis of the Krichevsky-Kasarnovsky equation.« less